- Martini, Luca, 1980-1
- Mary, Blessed Virgin, Saint, in the liturgy1
- Mary, of Bethany, Saint1
- Mass (Music)1
- Mass--Celebration1
- Massacre of the Holy Innocents in art1
- Masses1
- Masses, Unaccompanied1
- Mathematical recreations1
- Mathematics, Greek1
- Mathematics, Medieval1
- Maurice, Saint, -approximately 2871
- Maxims1
- Maximus, of Turin, Saint, active 4th century-5th century1
- Medical astrology1
- Medical formularies1
- Medici, Bernardo d'Alamanno de'1
- Medici, Lorenzo de', 1449-14921
- Medicine, Ancient1
- Medicine, Medieval--Manuscripts1